1. Field
Example aspects described herein relate generally to an apparatus transferring traffic across a network, and more particularly to transferring traffic across a network which supports virtual concatenation (VCAT) services.
2. Description of the Related Art
Generally, the Synchronous Optical Network (SONET) and Synchronous Digital Hierarchy (SDH) transport hierarchies provide voice and private line services using time division multiplexing (TDM). TDM subdivides the bandwidth of an optical channel into smaller usable fragments called time slots.
In such TDM systems supporting different granularities, bandwidth fragmentation can be a problem. Conventionally, when there are different granularities involved such as Synchronous Transport Signal (STS)-1 and STS-3c equivalent members, a transport pipe is packed tightly with the different granularities starting at the first available timeslot(s) available to support the STS-1 or STS-3c member to completely utilize the transport pipe. This can maximize an initial configuration. However, bandwidth can get fragmented, as circuits are added and deleted, leaving behind holes in the transport pipe such that they are not consecutive or aligned to the correct STS-nc boundary. Over time, the network efficiency can be lowered as the free bandwidth is split into multiple non-contiguous slots, thereby causing new demands to be rejected.